This article explores the effects and mechanisms of magnolol on the proliferation of gastric cancer cells as well as the apoptosis. First, 0 (control group), 20, 40, and 80 /x mol/L magnolol were observed on SGC-7901 cells for 24, 48, and 72 h. We use MTT method to measure the cell viability, and apoptosis and cells were detected by flow cytometry. Cell proliferation inhibition rate, apoptosis and cell cycle experiments showed that P-value < 0.05 means the difference is statistically significant. And the results which compare the control group, the 20, 40, and 80 /x mol/L show that honokiol had lower cell viability (P < 0.01), increased apoptotic rate (P < 0.01), and cell cycle stay in the G1 phase (P < 0.01), so we found that honokiol may suppress the proliferation of SGC-7901 cells and stimulate apoptosis by regulating cyclin and apoptosis-related proteins. With the development of nanomaterials synthesis technology and application in biomedicine, gold magnetic composite nanomaterials have unique properties, so they have been widely concerned in many applications. We combine gold and magnetic nanomaterials through other nanostructures to achieve the integration of diagnosis and treatment of tumors. We have synthesized two kinds of gold magnetic nanocomposites, GNR-PPy-FA nanocomposites. With the role of chemotherapy and heat and light therapy, GNR-PPy-FA nanocomposites have high light-to-heat conversion efficiency. Cell experiments verify the effect of chemotherapy and photothermal treatment of composite nanomaterials. After incubation with gold magnetic composite nanomaterials, the cell survival rate of tumor cells decreased to about 15%. In addition, both types of gold magnetic nanocomposites have the ability to dually target cancer cells, and the modification of folic acid and cancer cell membranes makes the material more biocompatible.